Many petroleum refineries utilize a delayed coking unit to process residual oils. Delayed coking is a process for obtaining valuable products from the otherwise poor source of heavy petroleum bottoms. Delayed coking raises the temperature of these bottoms in a process or coking furnace and converts the bulk of them to coke in a coking drum. The liquid in the coking drum has a long residence time to convert the resid oil to lower molecular weight hydrocarbons which distill out of the coke drum. Overhead vapors from the coking drum pass to a fractionator where various fractions are separated. One of the fractions is a gasoline boiling range stream. This stream, commonly referred to as coker gasoline, is generally a relatively low octane stream, suitable for use as an automotive fuel with upgrading. The liquid products from this thermal cracking are generally more valuable than the coke produced. Delayed coking is one example of a process for recovering valuable products from processed oil using thermal cracking of heavy bottoms to produce valuable gas and liquid fractions and less valuable coke.
It would thus be desirable to provide a method and/or composition that would improve the yield of liquid hydrocarbon products from a thermal cracking process.